WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

[Xen-devel] Re: domU oom -> xvda1 read-only without any notice?

To: xen-devel@xxxxxxxxxxxxxxxxxxx
Subject: [Xen-devel] Re: domU oom -> xvda1 read-only without any notice?
From: Josip Rodin <joy@xxxxxxxxxxxxxx>
Date: Wed, 31 Mar 2010 09:44:57 +0200
Delivery-date: Wed, 31 Mar 2010 00:45:28 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <20100331073340.GA13507@xxxxxxxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <20100331073340.GA13507@xxxxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mutt/1.5.18 (2008-05-17)
On Wed, Mar 31, 2010 at 09:33:40AM +0200, joy wrote:
> Two days ago a resource-intensive process caused one of my new 2.6.32 domUs
> to crash and burn, so yesterday I recompiled the kernel with debug options
> and retried it. In the early hours of today, after a few hours of running
> the same process, the kernel noticed an OOM again and started killing Apache
> and PostgreSQL. Unfortunately what also happened was that the root partition
> (/dev/xvda1) was somehow marked read-only. I tried to remount it from within
> domU, but I just got:
> 
> % sudo mount -o remount,rw /
> mount: block device /dev/xvda1 is write-protected, mounting read-only
> 
> There are no messages in the kernel log on either the .32 domU or the .26
> dom0. What do I do, other than shutdown and re-create? How does one manually
> 'talk' to blkback to see what's up?

On the dom0 I found /sys/module/blkbk/parameters/{debug_lvl,log_stats}.
Echoing 1 into the latter got me:

[1053818.198356] blkback.1.hda1: oo 22161  |  rd 143219463  |  wr 70692159  |  
br    0
[1053818.556417] blkback.1.hda2: oo 45794  |  rd 41644778  |  wr -2072774999  | 
 br    0
[1053819.957581] blkback.2.hda1: oo 5277  |  rd 35391  |  wr 2396186  |  br    0

[1053828.277147] blkback.1.hda1: oo   0  |  rd  275  |  wr  592  |  br    0
[1053828.802488] blkback.1.hda2: oo   0  |  rd   50  |  wr 22689  |  br    0
[1053835.086327] blkback.2.hda1: oo   0  |  rd    0  |  wr   85  |  br    0

And so on. Another attempt at remount didn't provoke any reaction, and I had
also set debug_lvl.

-- 
     2. That which causes joy or happiness.

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel